A category of musical instruments known as keyboard percussion instruments includes marimbas, vibraphones, xylophones and glockenspiels. Referring to FIGS. 1 and 2, a keyboard percussion instrument 10 generally includes keys known as tone bars 14 that are supported on support rails 22 such that the tone bars 14 are allowed to ring freely when struck by a mallet (not shown). The tone bars 14 and support rails 22 may form a tone bar rail assembly (sometimes referred to as the “harp”). The keyboard percussion instrument may also include a frame 20 that supports the tone bar rail assembly. The keyboard percussion instrument 10 may further include resonators 15 mounted below the tone bars 14.
The keyboard percussion instrument 10 may also include a dampening system including a damper 30 to dampen the tone bars 14 and stop the ringing. The dampening system may include a pedal 34 for user actuation of the dampening. Examples of such keyboard percussion instruments are described in greater detail in U.S. Pat. Nos. 6,245,978 and 5,977,465 and in U.S. Patent Application Publication No. 2008/0105105, all of which are fully incorporated herein by reference.
The dampening systems in existing keyboard percussion instruments have suffered from various drawbacks. In particular, the dampers in these instruments often make initial contact with the tone bars at the ends of the tone bars. Some instruments use a flat felt damper that contacts the bars evenly and other instruments use a fluid-filled bladder that first contacts the ends and then swells to contact the tone bar closer to the nodes of the tone bar. Because the ends of the tone bars are often a point of maximum vibration, the dampening by initial contact at these locations may result in buzzing, which does not provide a desirable musical effect.
Another drawback of existing dampening systems is the dampening of the tone bars at different locations on the instrument at different times, which also detracts from the musical quality of the instrument. In particular, the top and bottom notes often do not dampen at the same time, and the sharps and naturals often do not dampen at the same time. The middle portion of the instrument often does not dampen at the same time as the ends of the instrument because of the deformation of the damper by directly pulling on the damper with the user actuation mechanism. When the damper is deformed by the force applied to the damper, for example, a dampening surface of the damper may not contact the tone bars evenly.
In existing keyboard percussion instruments, the feel of the damper system (i.e., the pedal resistance) cannot easily be adjusted. In some existing instruments, the only way to adjust the pedal resistance or response is to adjust the spring tension of the dampening system. Such adjustments to the spring tension of the pedal simultaneously and indiscriminately affect the dampening balance. Other instruments merely adjust the angle of pull, which may not improve the feel, leverage, and control of the damper system by the musician.
A further drawback of existing keyboard percussion instruments relates to the mounting of the support rails to the frame of the instrument. The existing instruments do not allow the tone bar support rails or entire harp to be removed or adjusted. The existing instruments also do not adequately prevent transmission of noise to the instrument frame and/or resonators from the impact of the mallets upon the tone bars.